we were doing the same thing and at 1.5 like clock work she would wake up ready for more! Ped said just to try and an ounce more and see how she does. We are at 3 oz now and doing better but still eating every 2 hours during the day, anywhere from 3-6 hours between 3 oz bottles at night.

There is no manual for babies! Trial and error is the only way to go. If the 3 oz is too much you'll see increased spitting up or they won't be able to finish the bottle. Give it a try and see if it works!

I should mention my Ped pointed out that the 2-3 oz "rule" now is just an average and there will be babies that want more or less than that.

my daughter is 3wks and eating anywhere between 2-3 oz every 1.5-2hrs. she was a 36wkr and on neosure. dr said to just feed her when she gets hungry not to focus on the timeframe HOWEVER i feel like we're going backwards bc she started out with 1oz every 3-4 hours. I get very little (i mean no) sleep now